Austropotamobius torrentium

→  carapace with a single postorbital ridge without distal spine
→  rostrum converging distally, smooth without a median carina, short apex

Astacus astacus

→  carapace with two distinct postorbital ridges, second pair often distally blunt
→  rostrum with almost parallel margins, prominent median carina, long apex

Astacus leptodactylus

→  carapace with two distinct postorbital ridges, with obvious distal spine
→  long and narrow rostrum with almost parallel margins, prominent median carina, long apex

Non-indigenous crayfish species (NICS)

Orconectes limosus

→  carapace with a single postorbital ridge with obvious distal spine
→  margins of rostrum almost parallel without median carina, long and acuminated apex

Procambarus virginialis

→  carapace with a single postorbital ridge with distal spine
→  elongated rostrum with smooth margins, median carina absent, triangular apex

© Lucian Pârvulescu